Per- and poly-fluoroalkyl substances (PFAS) do not accumulate with age or affect population survival in ruddy turnstone (Arenaria interpres)

Per- and poly-fluoroalkyl substances (PFAS) may threaten wildlife due to their high environmental persistence, toxicity potential and potential to bioaccumulate. Bioaccumulation may be particularly profound in long-lived animals inhabiting higher trophic niches. To date, there is a paucity of data on PFAS bioaccumulation potential in individual wild birds over their lifetime. In this study, we analysed within-individual PFAS contamination in a declining long-distance migratory shorebird, the ruddy turnstone (Arenaria interpres), and the variation in PFAS contamination with age by repeatedly sampling 19 individuals throughout their lives between 2007 and 2022. We found blood-sampled turnstones on their non-breeding grounds in King Island, Tasmania, exhibited no variation of PFAS contamination with age, with low overall circulating PFAS concentrations (<0.015-25 ng/g, median: 0.78 ng/g). Moreover, irrespective of the increased PFAS usage along the East Asian Australasian Flyway over the past two decades, ruddy turnstone survival remained consistent throughout the 15-year sampling period, with no temporal trend in percentage of juveniles in the population. From a conservation perspective, low concentrations of PFAS found in this study are good news as they suggest PFAS alone do not seem to threaten turnstone survival. However, the unknown effects of exposure to mixtures of pollutants may yet threaten turnstones.